The present invention relates to the construction of rotating machines, and particularly to the installation of annular seals on a stationary part of the machine.
The purpose of such seals is to inhibit the flow of fluid around a rotating part. By way of example, such seals are employed in turbines to prevent the driving fluid, e.g. steam or gas, from bypassing the turbine blades. The effectiveness of such a seal depends on the precision of the gap formed with the rotating part. One factor influencing the size of this gap is the eccentricity between the axis of rotation of the rotating part and the geometric axis of the stationary part. It is generally impossible, for economic reasons, to completely eliminate this eccentricity. Heretofore, it has been necessary to tolerate a relatively large gap between the seal and the rotating part or to perform costly and time-consuming machining operations on the seal.